Actually.. I think all that demonstrates is that the truck with more weight on the back tires(more traction) wins, and that is the crew cab of course.

 

Er, you might try advancing the cam timing 4 degrees? :)

I did that to my '91 Bronco 351w, ZF swap, 3.55 gears with 265/85-16E's
~32 inch tires. I'm going to 3.73 gears as soon as I can and that change
will make it feel like 30 to 30.5 inch tires.

What the cam timing change did was made it feel less-powerful because
it got rid of its "pipey hit". So, that made it less-fun to drive in a way, but
made it a much better travel-rig and grocery-getter tho. :)

It can pull pretty good from 35mph now in 4th gear (1:1). :)

Before there were too many speeds/situations where there was no-right
gear to be in. :/ It sucked for everything except when it was on-the-pipe
-and- I wanted to floor it.

I don't recommend this 4* cam timing advance for automatics.

Cloyes Gear 9-1138

----------------------------------

That and the 205* thermostat change, upped my gas mileage. The old
thermostat was a 195*F but it was bad and acting more like a 180*. :/
The new thermostat was supposed to be 195* but tested out at 205*.
The bad thermostat was new too, but I didn't test it! :(

Before blaming everything on Ford, it's best to make sure everything is
right on your particular 351w first.

Alvin in AZ

 

on the same token, if you're wanting diesel power, you're gonna be unhappy with anything but a diesel. I'm a straight six guy through and through. and I love my 4.9. On the other hand, I also love the 5.9 cummins in my super duty (another straight six...). The 7.3 is the last true diesel ford sent out before the 6.7...

Find an OBS with forged rods and do the swap. Nothing else will ever give you the satisfaction you want...

I know this guy with a 7.3 thats running great that'd be open to a cheap sale, or the right trade... And I'm, I mean he's, easy to get a hold of most of the time too. If you want true power potential don't let go of your goal, and get the diesel. If you want the best all around bronco for your lower dollar, build the 351. If you want dead reliable and simple, do the six. they're all good choices. which do YOU want?

 

Cool, thanks! :)

How far to the left do you suppose a 4 degree cam timing advance would
shift those graphs? Especially the 351w/5.8's? :)

Alvin in AZ

 

Well, I was madly in love with the 400 in my F150.. I wish they had fuel injected it AND gas was $2 a gallon, I'd swap one in my Bronco in a heartbeat.

Thinking about it, the 300 is basically a 400 with two fewer cylinders. I bet I'd love a 300 stroker... ill probably do it one day, supercharge a 300 stroker.. after I marry a supermodel and make my millions, ya know.

 

The 300 is already a "stroker"! Ford did all that work for you... the shorter stroke inline 6 is the 240 which is identical in almost all other respects.

 

but these are big trucks, as strong and big as it is for a 6 cylinder, it's still only a 6 cylinder. (edit: I should have said, it's still only 300ci instead of 'only 6 cylinder'!)

Anyways, putting money into any motor is never a bad thing. I imagine the 300 with a few grand in performance parts would make for one heck of a motor.
Like I said, if only Ford had made a 4'' bore, 4'' stroke 8 Cylinder motor for us truck people, it would have been awesome.. I think we all would have appreciated it? Who cares about horsepower as truck people anyways! I know for a fact it would have been a huge hit! hmmm (and yes, that was sarcasm :P)

 

Check with the boys at FordSix. They will tell you that you aren't gonna get any significant increase in stroke out of a 300. Boring it over there is actually a good bit of room as I understand it without risking "hot spots".

Yes, it would have been nice... closest they ever came in a gaser was the 460.

Now my Cadi's had 472's and those had 4.30" bore and 4.06" stroke and would kick a 6800 lb. car in the @$$ and send it down the freeway like a rocket even if the A/C was running full tilt and you had six people in the car. In '68 when they were introduced the CR was damned near high enough to run them on propane at 10.5-1.

 

I currently have a 88 F150 300 4.9 and I am in Love it has a 73 mm turbo straight piped out the rear and inter cooler and when I did the build on dyno before install it produced 700hp 860ft lbs of torque at 18 psi boost and she will flat out haul. Especially after I had the 5 speed transmission rebuilt with a stage 3 racing clutch and she is my Daily Driver and thanks to a silencer you never hear the turbo spool until it’s too late

 

[QUOTE=ErrorS;10317925]That sort of makes me think I'll get that lowend torque I'm looking for, 260ft lbs at 2000rpms is insane for a 6. Is the 351w putting out 260ft lbs under 2500rpms? I just want a relatively flat curve, the 351w feels more like a potential race motor.

I loved the 400 in my 78, been chasing that kind of power for a long time. That motor had nothing behind it on paper, but when being used it was a beast. I don't care about that torque boost you get at 2500RPMs or so with the 351, I can feel it well, I know the power is there but it doesn't get moving quick enough.
honestly, I just don't like the 351. I get no torque at lowend, a kick in the butt at around 2500RPMs, then it goes flat at about 3500RPMs, it's tough keeping it in its power band with an auto offroad, really tough. I dunno, I just don't like the way it feels under my foot, I guess it's tough to explain.
Then with bigger tires keeping at speed in overdrive or 3rd is a pain with this motor, it just doesn't feel like it was built for what I'm using it for. I have to drop it to second to get it up to speed on the highway, which everyone knows isn't fun finding gears with an auto.
Regear isn't an option until I finalize my tire/suspension setup, which might take a while.

The motor is going out, it's the next thing to be replaced.. been wanting to do a diesel swap since I got my first Bronco a few years ago, it never happened. The time is coming to put a motor in my 90s and I want ot make sure I make the right move. Though, I'll PROBABLY just get my 351w rebuilt, I want to put some thought into a 300.[/QUOT
All I can say about all this talk is in my 1970 F100 4x4 has a 4.9l/300ci powerplant has all the torque I ever needed. My 400M blew a rod at 70,000 miles I guess that's typical. My 351W had power and torque. Middle of the road okay. My 4.9l/300ci has all the power and torque I wanted. If I wanted to I could pull down a telephone pole. The 435 new process transmission behind the 300ci. Drop it in 4 wheel drive put it in first gear and get out and walk beside it. In the woods. Spooks out the deer. Then drive right out of the ravine. A friend gave me a 390 to put in it... I sold the 390. Stayed with the 4.9l/300ci. Best power for my buck. Good luck with your experiments